Passing Array to Python Spark Lit Function

Question

Let\'s say I have a numpy array a that contains the numbers 1-10. So a is [1 2 3 4 5 6 7 8 9 10].

Now, I also have a Python Spark dataframe to which I want to add my num

Answer 1

In scala API, we can use "typedLit" function to add the Array or map values in the column.

// Ref : https://spark.apache.org/docs/latest/api/scala/index.html#org.apache.spark.sql.functions$

Here is the sample code to add an Array or Map as a column value.

import org.apache.spark.sql.functions.typedLit

val df1 = Seq((1, 0), (2, 3)).toDF("a", "b")

df1.withColumn("seq", typedLit(Seq(1,2,3)))
    .withColumn("map", typedLit(Map(1 -> 2)))
    .show(truncate=false)

// Output

+---+---+---------+--------+
|a  |b  |seq      |map     |
+---+---+---------+--------+
|1  |0  |[1, 2, 3]|[1 -> 2]|
|2  |3  |[1, 2, 3]|[1 -> 2]|
+---+---+---------+--------+

I hope this helps.

Answer 2

for loop in array inbuilt function

You can use array inbuilt function as

a = [1,2,3,4,5,6,7,8,9,10]
df = spark.createDataFrame([['a b c d e f g h i j '],], ['col1'])
df = df.withColumn("NewColumn", F.array([F.lit(x) for x in a]))
df.show(truncate=False)

You should get

+--------------------+-------------------------------+
|col1                |NewColumn                      |
+--------------------+-------------------------------+
|a b c d e f g h i j |[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]|
+--------------------+-------------------------------+
root
 |-- col1: string (nullable = true)
 |-- NewColumn: array (nullable = false)
 |    |-- element: integer (containsNull = false)

Using udf function

#udf function
def arrayUdf():
    return a
callArrayUdf = F.udf(arrayUdf, T.ArrayType(T.IntegerType()))

#calling udf function
df = df.withColumn("NewColumn", callArrayUdf())

output is same as with for loop way

Updated

I am pasting @pault's comment given below

You can hide the loop using map: df.withColumn("NewColumn", F.array(map(F.lit, a)))